Malaria is a disease transmitted by mosquitoes. It can cause severe symptoms and if left untreated, it can be fatal. If you practice good insect bite avoidance and take malaria tablets you are unlikely to get ill. However, it is good to know which signs you should look out for during your trip. Find out how to spot the first symptoms and what to do if you get ill.

Which symptoms are typical for malaria?

The most typical symptoms of malaria are:

  • fever
  • sweats and chills
  • headache
  • feeling tired or exhausted
  • stomach problems such as nausea and vomiting
  • diarrhoea
  • lack of appetite
  • muscle aches

The first sign of malaria most patients notice are flu-like symptoms, with chills followed by a high fever which persists for several hours.

Which other symptoms you encounter depends on which malaria parasite is causing the infection as well as your general health. Children are more likely to suffer from diarrhoea and nausea as a result of malaria than adults. People who live in malaria areas often develop a certain level of immunity and cease to show many symptoms when they contract the parasite. However, it is still possible for them to suffer from severe symptoms.

Expats who return to a malaria area where they grew up are particularly at risk as they tend to have lost their immunity but often fail to realise that they need to take precautions. It is important to take malaria tablets when travelling to a malaria area, even if you used to live in a country where the disease is endemic.

The parasite which causes the most severe symptoms is the malaria falciparum parasite, which can be fatal.

Malarial fever

Fever is a typical symptom of malaria and most people who suffer from malaria experience it. Fever and chills are often the first symptoms people notice.

How the fever manifests itself depends on which type of malaria parasite is causing it. Patients who carry the falciparum parasite often have a constant fever, while the other parasites may cause fever symptoms to occur in cycles.

While the cyclical pattern is typical for malaria, constant fever is easily misinterpreted as a viral or bacterial infection. If you develop a fever, you need to visit a doctor to get diagnosed and treated.

How soon after infection do the symptoms start?

The malaria parasite can cause symptoms as early as 9 days after you have been bitten by an infected mosquito but it can also take several weeks before the first symptoms appear. In rare cases it has been observed that symptoms didn’t occur until months or even up to a year after the exposure.

How soon the symptoms appear also depends on the type of parasite. The incubation period (between the bite and the first noticeable symptoms) for the different parasites are typically as follows:

Plasmodium falciparum - 9 to 14 days

Plasmodium knowlesi - 11 to 12 days

Plasmodium vivax and Plasmodium ovale - 12 to 18 days

Plasmodium malariae - 18 to 40 days

How long after infection can symptoms occur?

Malaria symptoms usually occur within 9 to 40 days after you have been bitten by an infected mosquito. However, there are exceptions. There have been reports of patients who were infected with the ovale parasite experiencing symptoms as many as four years after they were infected.

If you experience malaria symptoms, you should always seek medical attention and mention that you may have been exposed to the parasite.

Will the symptoms recur?

With some types of malaria, the chills and fever typically recur in a cyclical pattern. This is especially common with plasmodium vivax, plasmodium ovale as well as plasmodium malariae. It may also occur with plasmodium falciparum but may be masked by a constant fever.

The cyclical pattern occurs due to the parasite’s life cycle. When you are bitten by an infected mosquito, the parasite enters your bloodstream and travels to your liver. The parasite multiplies in your liver cells and eventually releases more parasites, which enter your red blood cells.

With plasmodium vivax and ovale, the symptoms usually recur every 48 hours. With plasmodium malariae, they typically return within 72 hours. It is important that you speak to a doctor straight away if you notice malaria symptoms. Even if you temporarily feel better you may still have malaria and your condition is likely to worsen again.

What to do when you notice malaria symptoms

If you experience malaria symptoms at any point during or after your stay in a malaria area you need to seek medical attention immediately - even if your trip was several weeks or even months ago. It is important that you point out that you have been travelling so your doctor knows which illnesses to check for.

If you are planning a trip to a remote location without access to medical facilities you may need to consider taking a malaria treatment with you in case your prophylaxis fails. Malaria needs to be treated without delay and having a treatment at hand for emergencies will help you stay safe while travelling in remote terrain.